Pulverizer mill

ABSTRACT

A pulverizing mill is provided with a spider frame which is mounted on the main pulverizing rollers. Flexibly secured to the spider frame are spacer means which are positioned between the rollers.

Francis M. Barton Parsippany, NJ.

Sept. 25, 1969 Foster Wheeler Corporation Livingston, NJ.

PULVERIZER MILL 6 Claims, 5 Drawing Figs.

US. Cl

Inventor Appl. No. Filed Patented Assignee 241 103, 241 123 1111. c1 1302c 15 00 Field of Search 241 103,

[56] 1 References Cited UNITED STATES PATENTS 1,049,051 12/1912 Clark 241/103 2,115,314 4/1938 McErlean. 241/103X 3,458,142 7/1969 Berz 241/103 Primary Examiner-Robert C. Riordon Assistant ExaminerMichael Koczo, Jr.

Att0rneys.lohn E. Wilson, John Maier, Ill and Marvin A.

Naigur ABSTRACT: A pulverizing mill is provided with a spider frame which is mounted on the main pulverizing rollers. Flexibly secured to the spider frame are spacer means which are positioned between the rollers.

PATENTEDUEHZIBYI 3 13417 SHEET 2 OF 2 FIG. 2

INVI'JNIUH.

FRANCIS M BARTON BACKGROUND OF Til-IE INVENTION In connection with the operation of relatively large coalfired furnaces which are used in vapor-generating systems in the utility industry for production of electricity, it is necessary to supply finely powdered coal to the combustion chamber of the furnace. The raw coal feed stock is usually reduced to comminuted particles in a pulverizer apparatus which generally consists of a rotating grinding table on which there is formed a grinding surface, relatively heavy rollers are journaled within the apparatus in contact with the grinding surface. It has been the usual practice to provide a system for separating the rollers in the pulverizer apparatus, such that each of the rollers can be maintained in contact with the grinding surface. This has usually been accomplished by a center shaft arrangement which is used to support blocks that were interposed between the rollers. In accordance'with the present invention, the center shaft construction has been eliminated by providing spacer means which are indirectly supported by the rollers. In this manner, it is possible to eliminate the center shaft arrangement with its associated maintenance and operating problems.

SUMMARY OF Til-IE INVENTION In accordance with illustrative embodiments demonstrating features and advantages of the present invention, there is provided a pulverizing mill comprising a housing in which a plate having a grinding surface is mounted for rotation. Means are provided for rotating the plate and for introducing material to be pulverized into the housing and onto the grinding surface. A plurality of rollers each having a peripheral grinding face are adapted to contact the grinding surface of the plate. A spider frame surrounds the rollers, and means are supported by the spider frame for mounting on the roller. Spacer means are flexibly secured to the spider frame between the rollers such that the rollers are separated and maintained in contact with the grinding surface.

BRIEF DESCRIPTION OF THE DRAWINGS The above brief description, as well as further objects, features, and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in connection with the accompanying drawings wherein:

FIG. I is a front sectional view of a pulverizing apparatus embodying features of the present invention, in which the hexagonal spider frame embodiment is shown;

FIG. 2 is an enlarged plan view of a portion of the hexagonal spider frame, which is removed from the pulverizing apparatus shown in FIG. ll;

FIG. 3 is an enlarged side elevational view of a single-bearing plate, shown in FIG. 2, mounted on a roller;

FIG. 4 is an enlarged partial plan view of a circular spider frame in accordance with a further embodiment of the present invention, which is shown removed from the pulverizing apparatus; and

FIG. 5 is a side elevational view of the embodiment shown in FIG. 4 with a single-bearing plate mounted on a roller.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FllG. 11, there is shown a pulverizer mill, generally designated 40 in which there is mounted the first embodiment of the spacer support of the present invention generally designated it. The pulverizing apparatus includes a steel housing 12 which is positioned at ground level for enclosing a support E3 on which there is rotatably mounted a grinding table 114. Raw coal feed is introduced into the housing 12 through a conduit system ll5 which is positioned above the grinding table B4. A grinding ring 16 is rotatably carried on the upper surface of the table 114, and the upper surface of grinding ring 16 if formed with a concave annular grinding recess or track 18.

A plurality of spaced-apart pulverizing rollers 20, preferably three in number, ride on track 18 and each of the pulverizing rollers 20 is formed with an outer recess 22 in which there is provided an inner annular ring shaped track 24. Each of the rollers 20 has secured thereto a bearing collar 26 provided with a peripheral groove 27 which engages the complimentary surface of a pressure ring 28.

The pressure ring 28 has a plurality of spaced slotted lugs 29 in the outer periphery thereof, into which project tongues 30. The tongues 30 are secured to steel housing 12 inwardly therefrom toward slotted lugs 29 to prevent rotation of pressure ring 23. Spaced above pressure ring 28 is a thrust ring 31 which has a plurality of spaced tongues 32 extending from its periphery, which project into a plurality of slotted lugs 33 that are mounted on and extend inwardly from the housing 12. As the slotted lugs 29 and tongues 30 cooperate to vertically guide and prevent rotation of pressure ring 28, similarly, the slotted tongues 32 and lugs 33 cooperate to prevent rotation of thrust ring 31, and to guide the thrust ring 31 in its vertical movement. Interposed between the pressure ring 28 and thrust ring 31 are a plurality of spaced compression springs 34 which maintain pressure ring 28 and thrust ring 31 in spaced relationship and provide a downward thrust upon each of the rollers 20 through pressure ring 28. A baseplate 37 is secured to the housing 12 and a holddown rod 38 connects thrust ring 31 with baseplate 37, and is provided with an adjusting nut or turnbuckle 40.

As shown in FIG. 2, the spacer support 11 includes a hexagonally shaped spider frame 42 and has secured to the inside thereof a bearing plate 44 at the comers thereof, and wheels 48 are joumaled on axle studs 46 such that the wheels 48 can be mounted in rolling contact with groove 27.

As shown in FIG. 3, each of the bearing plates 44 is formed with slotted openings 50 through which the bearing plates 44 are loosely bolted by a nut and bolt connection 51 on a spider frame 42 to act as a nonrigid floating mounting frame.

Fixed to the spider frame 42 between adjacent rollers 20 are supports 52, each of which is preferably a single leaf spring on which there is respectively mounted spacer blocks 54. It is preferable to rigidly mount one of the plates 44 to the spider frame 42, such as by welding a bearing plate 44 to spider frame 42, and the other two plates 44 should be flexibly mounted to spider frame 42 to allow for misalignment between the three rollers 20.

In FIGS. 4 and 5 there is illustrated a further embodiment of the invention in which corresponding parts have been designated by the same reference numerals as part of a series. In this form of the invention a Y-shaped spacer support llllll includes a spider frame 142 which is circular, and a bearing plate 144 having a Y-shaped configuration, with three legs 145 secured to the inside portion of spider frame 142.

Secured to each of the legs 145 is an axle stud 146 for journaling a twin-roller 14$ which includes an inner roller 148A and an outer roller 148B that form an annular groove 149, therebetween. As best shown in FIG. 4, the annular groove 149 of twin-roller 1148 rides on track 24.

In FIG. 5 there is shown the bearing plate 144 which is formed with a slotted opening 150 through which the bearing plate 144 is secured on the spider frame 142, as a floating mount by means of a nut and bolt connection 151. Fixed within the spider frame 142 between adjacent rollers 20 are hinge supports 152, on which there is mounted a spacer block 154 by means of a hinge connection I56. By progressively inspecting FIGS. l and 4 it can be appreciated that the Y-shaped spacer support 111 can be mounted on the rollers 20 in FIG. I by positioning annular groove 149 in the track 24.

What is claimed is:

1. Apparatus for pulverizing material into comminuted particles comprising a housing, a table having a grinding surface mounted in said housing for rotation, means for rotating said table, means for introducing said material into said housing in contact with said grinding surface, a plurality of rollers each having a peripheral grinding face adapted to contact said grinding surface, a spider frame surrounding said rollers, plate means mounted on said rollers loosely supporting said spider frame and spacer means flexibly secured to said spider frame between said rollers such that said rollers are separated and maintained in contact with said grinding surface.

2. Apparatus according to claim 1 in which said rollers are formed with an outer peripheral groove, and said plate means is formed with a substantially flat surface and includes a plurality of wheels joumaled on said flat surface such that said wheels can be mounted in rolling contact with said groove.

3. Apparatus according to claim 2 in which said spider frame and plate means are formed with coextensive through openings, and bolts are mounted in said through openings for relatively loosely connecting said plate means to said spider frame.

4. Apparatus according to claim 1 in which there are three of said rollers, said spider frame is hexagonally shaped, and each of said spacer means includes a spacer block and a leaf spring mounted on said spider frame.

5. Apparatus according to claim 1 in which an inner annular ring shaped track is formed on each of said rollers, and said plate means is formed with a substantially flat surface and includes a plurality of rollers each of which is fonned with an annular groove for riding on said track.

6. Apparatus according to claim 5 in which said spider is circular shaped, said plate means is Y-shaped and includes three legs for mounting said rollers, and each of said spacer means includes a spacer block and a hinge connection between said spacer block and spider frame. 

1. Apparatus for pulverizing material into comminuted particles comprising a housing, a table having a grinding surface mounted in said housing for rotation, means for rotating said table, means for introducing said material into said housing in contact with said grinding surface, a plurality of rollers each having a peripheral grinding face adapted to contact said grinding surface, a spider frame surrounding said rollers, plate means mounted on said rollers loosely supporting said spider frame and spacer means flexibly secured to said spider frame between said rollers such that said rollers are separated and maintained in contact with said grinding surface.
 2. Apparatus according to claim 1 in which said rollers are formed with an outer peripheral groove, and said plate means is formed with a substantially flat surface and includes a plurality of wheels journaled on said flat surface such that said wheels can be mounted in rolling contact with said groove.
 3. Apparatus according to claim 2 in which said spider frame and plate means are formed with coextensive through openings, and bolts are mounted in said through openings for relatively loosely connecting said plate means to said spider frame.
 4. Apparatus according to claim 1 in which there are three of said rollers, said spider frame is hexagonally shaped, and each of said spacer means includes a spacer block and a leaf spring mounted on said spider frame.
 5. Apparatus according to claim 1 in which an inner annular ring shaped track is formed on each of said rollers, and said plate means is formed with a substantially flat surface and includes a plurality of rollers each of which is formed with an annular groove for riding on said track.
 6. Apparatus according to claim 5 in which said spider is circular shaped, said plate means is Y-shaped and includes three legs for mounting said rollers, and each of said spacer means includes a spacer block and a hinge connection between said spacer block and spider frame. 